KR840002631Y1 - Fire brick for rotary kiln - Google Patents

Abstract

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Description

Firebrick for rotary kiln

1 is a perspective view showing a conventional brick shape.

FIG. 2 is a partial cross-sectional view taken along line II-II of FIG. 1 showing the production situation of a furnace using a conventional brick.

3 is a perspective view showing one embodiment of a brick.

4 is a partial cross-sectional view taken along line IV-IV of FIG. 3 showing the creation of a furnace using the brick of FIG.

5 and 6 are perspective views showing another embodiment of a brick.

7 is a perspective view showing a steel plate used between bricks.

8 is a perspective view showing another embodiment of a steel sheet with a brick;

9 is a perspective view showing a sun using corrugated cardboard, asbestos, etc. between the steel sheet and the brick according to the present invention.

10 is a perspective view showing an assembled state of a steel plate and a brick.

The present invention relates to a refractory brick used in a rotary furnace such as a cement rotary kiln, and more particularly to its shape and configuration.

Grooving grooves are installed in the largest flat part of the refractory bricks to protect the refractory bricks by premature attachment and stabilization of coatings, and increase the heat insulation effect of the coatings, thereby improving the fireproof brick's durability and heat dissipation. To reduce energy consumption.

In a rotary furnace including a cement rotary kiln, which is one of the energy-saving industries, the reduction measures are particularly taken in the recent oil situation.

The cement rotary kiln will be described as an example. The cement kiln is changed from a kiln to a rotary furnace, and transitioned from a wet kiln to a dry kiln with a preheater via wet, semi-dry, and dry. The development of the technology is so remarkable that no one else can see it. For this reason, it is known that the fuel raw unit per ton of cement clinker is also significantly reduced to less than 80 l / t from 120 l / t. However, despite the deterioration of fuel cost accompanied by the development of such device technology, the recent energy situation requires more energy saving. On the other hand, the development of device technology has reached its peak by the completion of the NS P method, and there is little room for improvement.

The heat balance for the current NSP type kiln is shown in the table below.

TABLE 1

Thermal system results (Kiln-type average *) Unit 10 ³ kcal / clinker / ton (%): Ratio (%)

* `` Investigation into SP Kiln '' page 78 digestion by Cement Association fuel specialty society report T-12 January 51

The first table shows how important it is to reduce the amount of heat dissipated.

This heat dissipation occupies most of the body of the rotor kiln. That is, in order to save energy of these rotary furnaces, the heat insulation measures for reducing heat loss from the iron shell of a rotary kiln are essential.

In cement rotary kilns and the like, fire-resistant heat-resistant bricks have already been used, but all have low-temperature zones, and are inferior to fire bricks generally used in terms of contents. In addition, there is a two-layer winding method in which fire bricks of low thermal conductivity are arranged on the side of the steel shell, but they are rarely employed in large diameter kilns because they are easily released from the "gap" with the built-in brick during use. In the baking table exposed to high temperature, there are also two-layer bricks in which the grooved part is provided on the back side of the refractory brick and the fireproof heat insulating material is attached thereto, and the so-called clogs and the bark side of the refractory brick are made of low thermal conductivity material. Low strength, not suitable for long-term operation.

Cement clinker is attached to the refractory used in the firing table of the cement rotorkilner, and coating is formed, but this coating has a thermal conductivity significantly lower than that of the refractory brick, so that the thermal insulation effect is obtained, thereby lowering the temperature of the refractory brick. Thus, the coating has two roles, energy saving and brick protection.

In the cement rotary kiln, the relationship between the thickness of the coating and the surface temperature of the shell is shown next.

Table 2 Relationship between surface temperature and coating thickness

Brick: Quality high temperature fired basic brick 200mm thickness

Iron shell: 40mm thickness, inner diameter 5,000mm (blackness of steel shell) = 0.85

Coating inner wall temperature = 1,450 ℃

Ambient temperature: 20 ℃ (non-wind) Thermal Conductivity: kcal / m · h · ℃ Brick = 2.35 Coating = 1.0

* Cement Association, Fuel Expert Committee Report T-10 "Investigation of Refractory for Rotorer Kilns" Page 46 Digestion March 47.

It is an object of the present invention to provide a brick having a shape and configuration in which coating is more easily and stably attached to a built-in refractory brick used in a rotary furnace.

Conventionally, the shape used for a rotary furnace is a buttercup type | mold and a fan type like the JIS also determined. Bricks used in the present invention are in contact with the adjacent bricks in their shape, one or two grooves are provided on one side or both sides of the brick surface of the side having the largest planar area, and the grooves extend in the radial direction At least open to the use surface. In the case where the grooves are provided on both sides, the adjacent bricks also have grooves that face each other in use. The groove may penetrate from the use surface to the steel skin surface or may end in the middle.

The purpose of this groove is to increase the contact area between the refractory brick and the workpiece (clinker) within a range that does not damage the contents of the brick, and also by coating continuously generated to the inside of the groove of the brick, The coating is firmly attached so that it does not fall easily. As a result, it becomes possible to improve the insulation and the durability of the brick.

In the conventional shape, even if a coating is attached, stability is lacking, and it falls easily by thermal shock, and as a result, a rapid temperature rise is given to a brick, which becomes a big factor of damage and a large heat loss. The shape and number of the grooves are determined by the properties of the workpiece and the material of the internal brick to be adapted and the shape thereof, but the shape should be easily filled in the grooves. When the filling is sufficient, a solid coating is formed on the heating surface and the recessed portion by the reaction of the brick or the like during use to achieve the desired purpose.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated about an Example shown.

The conventional brick shape is shown in FIG. 1, the furnace inner surface side, namely, the use surface of the brick 2 is shown with the code | symbol 3, and the iron skin side is shown with the code | symbol 4. As shown in FIG. FIG. 2 shows the production state of the coating 10 in which part of the kiln using the brick of FIG. 1 is cut according to arrow II-II of FIG.

As shown in FIG. 3, at least one (both in FIG. 3) or one or both (both in FIG. 3) of the largest planar portion 5 other than the use surface 3 and the iron-clad surface 4. 2 grooves 1 are provided. The recessed part 1 is open to the use surface 3, extends radially, and finishes without reaching the side of the steel surface 4, but may penetrate through it (FIG. 5). The number and position of the recesses can be appropriately selected as shown in FIGS. 5 and 6.

Cement rotary kiln. In a basic brick (magnesia, chromium, magnesia spinel) used in a firing table such as a lime rotary kiln, a steel sheet of steel is inserted as a base between the respective bricks. This is the role of expansion absorption using the creep properties of the steel sheet under high temperature, and the steel sheet reacts with the components in the brick to form minerals of low melting, and serves as a kind of adhesive, and serves to structure each brick one layer. Have

On the other hand, in the case of cement rotary kiln in addition to the steel sheet, it reacts with the clinker to produce a low melt, thereby promoting the production of coating. Therefore, the combined use with the steel plate 6 which processed the recessed part 7 so that a brick may conform to two recessed parts makes the effect more reliable. In addition, as shown in FIG. 8, when the portion 6a integrated with the steel sheet 6 used between the bases is extended to the use surface of the brick, the effect is further enhanced.

As described in FIG. 4, the premise that the coating 10 is formed by filling a clinker, such as a clinker, during use, forms the coating 10, but accelerates the attachment of the coating 10 in the groove. It is also possible to charge the material and leave it. This filler is based on the intermediate component of the fired material and the embedded brick, and may be added sulfides and carbonates of iron oxides or alkaline earth metals in order to facilitate the adhesion of chromium oxide or coating to add corrosion resistance thereto.

According to the present invention, the expansion absorbing table can be provided by the following considerations to the combination of the refractory brick 2 having the recesses 1 and the steel plate 6 having the recesses 7 according to the recesses. That is, as shown in FIG. 10, the depth dimension is applied to the recessed portion 1 of the steel sheet 2 without the steel sheet 6 being in close contact with the entire surface of the brick 2 having the recessed portion 1, It is assumed that the depth of the groove 1 and the necessary thermal expansion absorption portion are added together. In the construction, the steel plate 6 is supported by the bottom of the recess 7 at the bottom of the recess 1 of the brick 2, and the other part only floats on the expansion absorbing portion to support the adjacent brick. In this case, a material used as a normal expansion absorber such as corrugated cardboard or asbestos on the use surface side of the steel sheet as shown in FIGS. It is preferable to attach 8) in advance.

The following effects are obtained by the shape of the brick as described above.

Compared with the conventional shape, there is less coating early dropping and dropping after attaching, more effective use of coating thermal insulation can reduce the raw fuel unit, and stable coating of coating is incorporated in the rotary kiln. The role of protection of the refractory bricks is to alleviate damage caused by thermal shock or chemical erosion, which enables long-term operation of the first floor, resulting in the reduction of the basic unit of the bricks, and saving of the refractory raw material equivalent to the groove part. This saves resources, thereby improving overall efficiency by reducing weight.

In addition, according to the present invention, an effect of providing an expansion absorption zone is obtained by providing a material 8 used as a normal expansion absorber such as corrugated cardboard or asbestos between the firebrick 2 and the steel sheet 6.

Claims (1)

One or both of the largest planar sections 5 of the bricks are provided with at least one recess 1 extending radially in the furnace and open to the use surface 3, and the dimensions of the bricks with the expansion absorber added to the depth of the bricks. Firebrick for the rotary kiln which has the groove part 1, and installed the steel plate 6 which corrugated board, asbestos, etc. were installed in the use surface 3 side on the recessed part 1 of the largest flat part 5 of a brick. .